As for comparing the PDA to a Laptop, it would in a sense be hard to do in the technical world we are living in today. While the laptop is bigger than the PDA it is still portable and easy to take from one place to another. However, with the PDA information that is on you laptop can be put on your PDA as well. You can use the PDA almost anywhere, yet with a laptop this could prove to be a problem in some cases.
A PDA is also easier to use in the sense, if you are in a class or business meetings and need to take a few notes, you could take the notes with the PDA faster than you could with a laptop. A PDA is obviously much lighter and carrying it with you for appointments and work or other information all day, compared to a laptop; the PDA would be lighter. Some laptops are getting lighter, but none are still as light as a PDA.
You can also listen to music on your PDA with a headset like a walkman, although you can listen to your music on a laptop as well and with a headset as well, unfortunately often times you have to bring the media player up, which in turn would entail starting your laptop up. There are benefits to your PDA compared to the laptop. Easier to manage and carry around. Information you put onto your lap top many times stays on your laptop, where as the PDA the information can be removed and put on a main computer so you free up memory on your PDA.
Viewing pictures on your laptop would definitely be better obviously because the screen is so much bigger, however there are PDA's with pretty good size screens and quality resolution so that the pictures can be viewed easily. Being held in the hand, makes the PDA easy to access files and other programs that are out of reach of the laptop or in some cases if there are several files on the laptop it can take longer for the laptop to load, where as a PDA only has so much memory and with a tap of the stylus most pictures and other files instantly show up on the screen.
Comparing a PDA to a Laptop has its good points, and to some degree bad ones too. Laptops obviously have more memory and can store more files. And today they are being made even lighter than they used to. However as far as being portable the PDA still has them beat. So, a lot of people say you can't compare the PDA to a laptop simply due to the idea that both have unique qualities and capabilities.